NEW YORK (CNN) -- Terrorists struck the United States Tuesday
morning in harrowing, widespread attacks that included at least
three commercial jet crashes into significant buildings.

In the first attack, a plane hit the north tower of the World Trade Center in Manhattan shortly before 9 a.m., followed by another plane into the second tower about 20 minutes later. Both towers later collapsed.

About an hour later, a plane crashed into the Pentagon, part of which later collapsed.

American Airlines told CNN that it lost two planes in "tragic accidents:" Flight 11 from Boston with 81 passengers and 11 crew aboard and Flight 77 from Washington Dulles airport with 58 passengers and six crew aboard. Both planes were en route to Los Angeles.

United Airlines Flight 93 airliner headed from Newark, New Jersey, to San Francisco, crashed near Somerset, Pennsylvania -- police said initial reports indicated no survivors. United also confirmed the crash of Flight 175 from Boston to Los Angeles.

The Pentagon, the White House, the State Department, the Justice Department, the Capitol, the CIA and all other government buildings in Washington evacuated.

President Bush cancelled an appearance in Florida to return to Washington, calling the crashes "apparent terrorist attacks" and "a national tragedy."

In the first ever national ground stop of aircraft, all flights nationwide have been stopped at their departure airports. All international flights were diverted to Canada.

Mullah Abdul Salam Zaeef, the Taliban ambassador to Pakistan, said in reaction to the news of the terror attacks that "we want to tell the American children that Afghanistan feels your pain and we hope that the courts find justice."

In New York, more than 10,000 rescue personnel rushed to the scene. The entire downtown area of Manhattan was evacuated as far north as Rockefeller Center, according to an official at an emergency command post.

NEW YORK (CNN) -- In what appeared to be coordinated acts of terrorism, two jets crashed into the twin towers of the World Trade Center, collapsing them Tuesday while another aircraft crashed into the Pentagon. Hundreds were injured or killed, if not more.

A fourth aircraft crashed in Pennsylvania with 45 people on board.

President Bush said the United States would "hunt down and punish" the terrorists responsible. U.S. Secretary of State Colin Powell cut short a trip to Peru to return to the United States. He also vowed,
"The U.S. government will find out who is responsible."

The U.S. military went on full alert. Two aircraft carriers left the Naval base in Norfolk, Va., in response to the attacks. At the Pentagon, witnesses said a plane crashed into what is known as the "Army Corridor," the building collapsed and there wase an undetermined number of casualties.

Bush, who wound up an tour in Florida that was to focus on education, did not return to Washington out of concerns for his safety but flew to an Air Force base in Louisiana. Later, Air Force One took from Barksdale Air Force Base, its destination unknown.

Officials in Washington said a "Continuation of Government" plan had been activated. The activation involves a fortified facility at Mount Weather, Va. There was no word whether any of the U.S. leadership or ranking military officers had been taken to the facility, but Congressional leaders were said to be assembling outside Washington.

WASHINGTON (CNN) -- Barbara Olson, a conservative commentator and lawyer, alerted her husband, Solicitor General Ted Olson, that the plane she was on was being hijacked Tuesday morning, Ted Olson told
CNN.

A short time later the plane crashed into the Pentagon. Barbara Olson is presumed to have died in the crash.

WASHINGTON (CNN) -- The first-ever grounding of all flights in the United States will remain in effect until at least noon EDT Wednesday due to security concerns following Tuesday's hijackings of airliners that were then crashed into buildings, the Federal Aviation Administration said.

WASHINGTON (CNN) -- The U.S. General Service Administration will reopen its federal buildings in Washington and all other regions -- except those in the New York City area -- on Wednesday, said Hap
Connors, an agency spokesman.

WASHINGTON (CNN) -- The nation's first-ever groundstop will remain in effect until at least noon EDT Wednesday due to security concerns following Tuesday's hijackings of airliners that were then crashed into buildings, the Federal Aviation Administration said.

NEW YORK (CNN) -- The identities of some of the victims of the worst terrorist attack on American soil began to emerge Tuesday evening, including the top executives of a California optical networks company, a Boston-based technology company, a top NBC executive producer and the wife of the United States' solicitor general.As the day drew to a close, it was still horribly unclear exactly how many people had died, but the number was clearly in the thousands.

WASHINGTON (CNN) -- Secretary of State Colin Powell, returning to Washington from his aborted trip to Peru and Colombia Tuesday, said there were "no specific warnings" to herald the multiple terrorist
attacks earlier in the day against the financial and military nerve centers of the United States, but he promised those responsible would be caught."You can be sure the U.S. government will do everything it can to find the perpetrators of this cowardly attack against innocent people and bring them to justice," he told reporters.

LOS ANGELES (CNN) -- Several Arab and Muslim groups in California received threatening phone calls Tuesday in response to the terrorist attacks on the World Trade Center and the Pentagon. Maha Elgenaidi, executive director of the Islamic Networks Group in San Jose, said "a lot of Islamic Centers have shut Web sites down because of the amount of hate mail they were getting." Her organization received two "hate" calls after the attacks. Elgenaidi said the first caller told her to "get the hell out of this country. You people have done nothing but ruin this country. You don't belong here. Your religion is vile and evil."

OKLAHOMA CITY, Okla. (CNN) -- In parts of the country, motorists lined up at gas pumps Tuesday following rumors of shortages that fueled skyrocketing gas prices in the aftermath of terror attacks in
Washington and New York. Fears that tanker trucks wouldn't make it from refineries to gas stations put a premium on fuel. In Oklahoma City, prices reached the two-dollar mark.

NEW YORK (CNN) -- At least 265 New York City firefighters were feared dead as a result of the attack on the World Trade Center, according to Andrew White, spokesman for the International Association of Firechiefs. IAFC Executive Director Gary Briese told CNN earlier the specialized city rescue companies who went into the fiery twin towers of the World Trade Center are unaccounted for and it is believed they were in the buildings conducting search-and- rescue missions when structures collapsed after two airliners
slammed into them. New York City's fire chief, deputy fire chief, the fire department chaplain, and the chief of special operations were all killed in the collapse, White said.

WASHINGTON (CNN) -- Government sources say senior administration officials told members of Congress that they believe the hijacked airliner that crashed in Pennsylvania was headed for another
government target, possibly the White House, the Capitol or the Camp David presidential retreat.

RAMSTEIN, Germany (CNN)-- Frankfurt's Messeturm, Germany's equivalent of the World Trade Center, was evacuated briefly Wednesday morning following a bomb threat. An anonymous caller at 9 a.m. said a device would explode at 9:20 A.M. Authorities quickly led employees out of the building.

WASHINGTON (CNN) -- An aide to Senate Democratic Leader Tom Daschle said Wednesday that both House and Senate are trying to schedule closed-door security briefings between members and officials from
the CIA and the FBI.

WASHINGTON (CNN) -- The director of the Federal Emergency Management Agency has sent rescue teams known for pulling survivors from earthquake rubble to the terrorist-disaster sites at the Pentagon and in New York City.

NEW YORK (CNN) -- The Securities and Exchange Commission told CNN that SEC Chairman Harvey L. Pitt believes the financial markets, including the New York Stock Exchange and Nasdaq, will be ready to
open for trading Thursday. However, an official decision has not yet been made.

WASHINGTON (CNN) -- The United States intercepted two phone calls made after Tuesday's terrorist attacks against the Pentagon and New York's World Trade Center, and the conversations were between
members of al Qaeda, an organization sponsored by suspected terrorist Osama bin Laden.

ATLANTA (CNN) -- Losses from Tuesday's terrorist attacks against the United States are expected to run into the tens of billions of dollars. Insurance comanies tell CNN that the industry considers what happened an act of terrorism -- not an act of war -- so they do plan to honor their customers policies.

GANDER, Newfoundland (CNN) -- More than 17,000 people who were passengers on dozens of international flights that were diverted from landing in the United States remain stranded in the province of
Newfoundland in Canada. The planes landed at Newfoundland airports Tuesday as U.S. airspace was shut down in the aftermath of terror attacks in Washington and New York.

VERO BEACH, Fla. (CNN) -- At least 10 FBI agents were searching two houses in this city in Florida in what appeared to be part of the investigation into the deadly terrorists attacks against the United States. The immediate neighborhood was temporarily evacuated after FBI agents knocked on doors and said there was a bomb scare. Residents have been allowed back in their homes.

BOSTON (CNN) -- The FBI has taken several people into custody in connection with the investigation into the deadly terrorist attacks against the United States. The individuals have not been arrested and they have not been described as suspects. Heavily armed police and FBI agents swarmed the Westin Hotel in the Copley Square area of Boston. Sources said several people were also taken into custody for questioning in Florida.

KABUL, Afghanistan (CNN) -- Officials of the Taliban, the hard-line Islamic rulers of Afghanistan, are appealing to the United States not to attack Afghanistan, CNN has learned. The plea came after an
international message was passed along to senior Taliban officials, who were meeting Wednesday with Pakistan diplomats.

NEW YORK (CNN) -- Giant brokerage firm MorganStanley's chairman and CEO, Philip Purcell, said Wednesday "a vast majority" of the 3,500 staff members who worked in two of the World Trade Center buildings, including one of the twin towers, got out safely after hijackers crashed two planes into the towers.

WASHINGTON (CNN) -- The United States reached out to Russia and Pakistan Wednesday in an effort to put pressure on the Taliban militia that is harboring Saudi exile Osama bin Laden in Afghanistan, State Department officials and diplomatic sources tell CNN.

BRUSSELS, Belgium (CNN) -- NATO has unanimously declared the hijack attacks on the U.S. to be an assault against all member states. Secretary-General George Robertson said the U.S. would receive
support for military action from its 18 NATO partners if it is found the assaults were committed by foreign nationals.

BALTIMORE (CNN) -- The Navy's medical ship USNS Comfort left Baltimore Wednesday bound for the New York City waterfront, according to the Military Sealift Command. The vessel is nearly 900
feet long and has 1,000 beds. It saw action in the Middle East during Operation Desert Storm.

NEW YORK (CNN) -- Top U.S. officials said Wednesday that they know the identities of many of the hijackers on each of the four flights that crashed Tuesday -- two toppling the World Trade Center and a
third heavily damaging the Pentagon in the worst terrorist attacks in U.S history.

NEW YORK (CNN) -- Rescue workers and journalists were evacuated from the devastated area around the World Trade Center amid fear that another building may collapse. The twin towers of the World Trade
Center collapsed Tuesday after hijacked jets crashed into them. Another adjacent building also later collapsed.

NEW YORK (CNNfn) - U.S. stock markets will stay shuttered for a third day Thursday and may not reopen until Monday, though officials from the major stock markets and the government said trading could
resume as early as Friday.

WASHINGTON (CNN) -- Federal officials Wednesday announced a limited resumption of commercial flights to allow travelers stranded around the country as a result of Tuesday's hijackings to return home. But
Transportation Secretary Norm Mineta temporarily extended all other aspects of the nationwide "groundstop" that halted all scheduled domestic flights until new security measures are put into effect at the country's airports.

WASHINGTON (CNN) --- Congressional leaders and the White House agreed Wednesday to set aside $20 billion for rescue efforts, repairs and counterterrorism work after Tuesday's terror attacks on Washington and New York.

WASHINGTON (CNN) -- In the wake of Tuesday's terrorism attacks on the World Trade Center and the Pentagon, the State Department Wednesday evening will reissue its Worldwide Caution warning Americans traveling abroad, a senior State Department official told CNN.

VERO BEACH, Fla. (CNN) -- Investigators have leads on four hijackers they believe commandeered the two airliners from Boston that destroyed the twin towers of the World Trade Center, CNN has learned. Two of the men were brothers apparently from Saudi Arabia who had most recently been living in Florida where they attended flight training school.

NEW YORK (CNN) -- Authorities evacuated the Empire State Building and Penn Station Wednesday night. Three police officers told CNN the Empire State Building was evacuated after a bomb-sniffing dog
detected a suspected explosive device inside one of the city's most popular landmarks.Shortly afterwards, police told people to get off the trains in Penn Station just a few blocks away and to "run as fast as they can," a CNN producer reported from the scene.

NEW YORK (CNN) -- Authorities evacuated the Empire State Building and Penn Station Wednesday night. Three police officers told CNN the Empire State Building was evacuated after a bomb-sniffing dog
detected a suspected explosive device inside one of the city's most popular landmarks.Shortly afterwards, police told people to get off the trains in Penn Station just a few blocks away and to "run as fast as they can," a CNN producer reported from the scene. About 20 minutes after the evacuation was ordered, the all clear was given at both locations.

NEW YORK (CNN) -- A doctor helping treat rescue workers Wednesday in a downtown office building told CNN the building was serving as a makeshift morgue, and contained about 150 bodies. Dr. William
Bradley, an ophthalmologist treating rescue workers' eyes, burning and scratched by the cloud of soot and fiberglass that envelopes much of Manhattan, said he saw the bodies inside the American Express building in Tribeca.

WASHINGTON (CNN) -- Dover Air Force Base in Delaware is preparing to receive bodies of victims killed in Tuesday's terrorist attack on the Pentagon, officials tell CNN. Spokeswoman Jennifer Hall says the
remains will arrive at the port mortuary starting Thursday afternoon, to be processed and identified "in the most honorable way by our mortuary affairs personnel."

KABUL, Afghanistan (CNN) -- Afghanistan's ruling Taliban movement is not confirming a widespread report out of the United Arab Emirates that suspected terrorist Osama bin Laden is under house arrest in
Afghanistan, but although it appears he is in the country, his exact location is unknown.

WASHINGTON (CNN) -- In an effort to assess the security of the U.S. nuclear weapons stockpile and review anti-terrorism efforts under way at U.S. nuclear power plants, a group of congressional leaders will visit U.S. nuclear weapons laboratories this weekend.

NEW YORK (CNN) -- Major internet service providers (ISPs) in the United States said Thursday they are cooperating with federal authorities in the investigation of Tuesday's terrorist attacks on New York and Washington.

WASHINGTON (CNN) -- U.S. Secretary of State Colin Powell went further than any member of the Bush administration Thursday in naming Osama bin Laden as a leading suspect in Tuesday's attacks on the World Trade Center and the Pentagon.

-- The White House and Congress have agreed on a $40 billion emergency aid package in the wake of Tuesday's terrorist attacks. Officials said the legislation should be ready for President Bush's signature Saturday.

WASHINGTON (CNN) -- All three New York area airports are now reopened, according to Federal Aviation Administration spokesman Alison Duquette. This includes LaGuardia, John F. Kennedy International Airport, and Newark International Airport.

WASHINGTON (CNN) -- People across the United States and around the world observed a day of "prayer and remembrance" Friday for the victims of the attacks on the World Trade Center and the Pentagon.

U.S. President George W. Bush joined members of Congress, top military officials, world diplomats and a host of dignitaries -- including former presidents Gerald Ford, Jimmy Carter, Bill Clinton and George Bush and their wives -- at a noontime prayer service at the National Cathedral in Washington.

New York (CNN) -- President George W. Bush went to New York City Friday to see for himself the devastation from Tuesday's terrorist attacks on the World Trade Center and boost morale for the rescue
and recovery effort. Earlier, the president told a prayer service at the National Cathedral that a "unity against terror is now extending across the world."